The present invention relates to a dehumidifier to be installed in a room such as a drying chamber and is used to dehumidify the air in the room.
A type of dehumidifier has been known in the past, according to which a chiller is cooled down by vaporization heat, i.e. by vaporizing a refrigerant in liquid state. Then, humid air sucked from outside is chilled down by a chiller, and the humid air is dehumidified by condensation of the moisture contained in the humid air by chilling. The refrigerant is then liquefied by compressor, and dry air thus dehumidified is heated by condensation heat generated at the time of liquefaction. Then, the dry air is discharged to outside.
However, in case of a conventional type dehumidifier, temperature difference between the temperature of the humid air sucked from outside and the temperature of the dry air, which has been chilled down and dehumidified, is risen. Thus, problems may arise that electric power consumption required for chilling and temperature rise after dehumidification would be higher.
The Japanese Patent Publication JP-A-2000-320861 discloses a dehumidifier, according to which, after allowing the external air as sucked through air suction inlet to pass and to be heated by passing through one-half portion of an approximately U-shaped condenser, the heated air is passed to an evaporator cooled down. Then, a vapor in the air is efficiently condensed on the surface of the evaporator and dehumidified by rising temperature gradient of the air, and the dry air thus dehumidified is heated by passing through another one-half portion of the condenser, and the dried air after heating is discharged to outside via an air discharge outlet.
Also, the Japanese Patent Publication JP-A-Sho36-21644 discloses a heat exchanger having a heat transfer unit, wherein projections are prepared at a distribution ratio as required on a flat plate, the flat plate is folded back in multilayers alternately with such width as required, a gap for the projection is formed between the flat plates, and the flat plates are heat boundary. In the heat transfer unit, high temperature fluid and low temperature fluid are passed through the gap, and heat exchange operation is performed via the heat transfer unit.